Judson l



(No Model.)

J. L. THOMSON.

.RIVET.

Patented Aug. 16, 1892..

\A/ TNESSEB: W9 $37M NITED STATES ATENT FFICE.

JUDSON L. THOMSON, OF WALTHAM, MASSACHUSETTS, ASSIGNOR TO THE JUDSON L. THOMSON MANUFACTURING COMPANY, OF SAME PLACE.

RlVET.

SPECIFICATION formingpart Of Letters Patent No. 481,123, dated August 16, 1892.

Application filed January 18, 1892. Serial No. 418,385. (No model.)

To all whom i may OOH 7%: end of the shank and gradually contracted Be it known that I, J UDsoN L. THOMSON, of in width toward the inner end of the shank. WValtham, in the county of Middlesex and When the shank is being driven into the State of Massachusetts, have invented certain leather, the pressure of the material 011 the new and useful Improvements in Rivets for tapered external surfaces of the prongs has Boots or Shoes, of which the following is a a tendency to bend said prongs inwardly, as specification. shown in dotted lines in Fig. 1, thus contract- This invention relates to rivets for boots ing the slot. It will be seen that the tapered or shoes, composed of a slotted tapered form of the slotprevents such contraction, be-

to shank and a head, bot-h formed in one piece, cause the larger end of the slot receives so the shank being circular in cross-section from much of the leather into which the rivet is end to end and made largest at its inner end driven that said material acts as a wedge or adjoining the head, the taper of the shank befilling, pressing outwardly against the sides ing gradual from its inner to its outer end. of the slot and preventing the inward bond- 15 Heretofore rivets of this form have been sloting of the prongs. ted to convert a portion of the shank into It will be observed that by usinga tapered clinching-prongs by forming aparallel-sided shank which is circular in cross-section from slot in the tapered shank, as shown in Letend to end I give each prong formed by the ters Patent No. 304,862. It is found that in slot in said shank a substantially semicir- 2o practice when the rivet is being inserted in cular outer surface and a fiat inner surface. the pieces of leather which it is to unite the This form gives the prongs the necessary pressure of the material on the tapered exstrength and freedom from liability to acciternal sides of the prongs has a tendency to dentally bend or cripple. bend said prongs inwardly toward each other, In Letters Patent No. 333,700, granted to 25 and thus so contract the outer end of the slot me January 5, 1888, I show in Fig. 2 a rivetseparating said prongs as to make the clinchshank having its external sides tapered in ing of the prongs a matter of some difficulty. wardly from the head toward the point, and

My invention has for its object to obviate provided with a tapered slot which enlarges this difficulty; and to this end it consists in from the head toward the point. The outer 30 providing the tapering shank with a corresides of said rivets are flat, however, and not spondingly-tapering slot, which is widest at semicircular, as in the present case. .I have the outer end of the shank and gradually defound by long experience that rivet-prongs creases toward its inner end, this form of slot having flat exterior as well as flat interior preventingthe inward bending of the prongs surfaces are not sufficiently reliable and are 3 5 caused by the contact of the material with liable to accidentally bend and cripple in a their external surfaces while the rivet is bemanner which seriouslyimpairs their usefuling inserted in the material. ness. I have therefore devised the rivet,

In the accompanying drawings, forming which constitutes my present improvement, part of this specification, Figure 1 represents to overcome the objections inherent in the 40 a side view of my improved rivet. Fig. 2 reprivet shown in my former patent. 9o resents a perspective view of the same. I am aware that a tapered rivet-shank The same letters of reference indicate the which is circular in cross-section from end same parts in both the figures. to end is not new, the same being shown in In the drawings, a represents the tapered Patent No. 304,862, above mentioned; but in shank, and b the head, of a rivet, the shank that patent the slot in the shank is ofuniform 9 5 being circular in cross-section. width from end to end, so that when the shank c 0 represent the prongs, which are formed is being inserted in the material the pressure by cutting a slot in the tapered shank. In of the material on the taperedexterior closes carrying out my invention I give said slot a the mouth of the slot to an ob ectionable detapering form, it being widest at the outer gree. It wlll be seen, therefore, that my surface, the inner and outer tapered surfaces of the rivet being substantially equal in angle, 1 5 whereby the points of the prongs are located centrally above the bases thereof, as and for the purposes set forth.

In testimony whereof I have signed my name to this specification, in the presence of 20 two subscribing Witnesses, this 13th day of January, A. D. 1892.

JUDSON L. THOMSON.

WVitnesses:

C. F. BROWN, A. D. HARRISON. 

